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| author | Steve Capper <steve.capper@arm.com> | 2018-01-11 13:11:57 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-01-14 21:49:51 +0300 |
| commit | 9dfe4828aa32c49856dffd6cd31297f3466caa0d (patch) | |
| tree | 5e2802e946a4d675f614922dc32580cdc44eced8 /arch/arm64/include/asm/uaccess.h | |
| parent | 79e9aa59dc29a995921fb01e64cd36b73cf5abe0 (diff) | |
| download | linux-9dfe4828aa32c49856dffd6cd31297f3466caa0d.tar.xz | |
arm64: Re-order reserved_ttbr0 in linker script
Currently one resolves the location of the reserved_ttbr0 for PAN by
taking a positive offset from swapper_pg_dir. In a future patch we wish
to extend the swapper s.t. its size is determined at link time rather
than comile time, rendering SWAPPER_DIR_SIZE unsuitable for such a low
level calculation.
In this patch we re-arrange the order of the linker script s.t. instead
one computes reserved_ttbr0 by subtracting RESERVED_TTBR0_SIZE from
swapper_pg_dir.
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/uaccess.h')
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 3821fab01d7d..01ade20d5456 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -108,8 +108,8 @@ static inline void __uaccess_ttbr0_disable(void) unsigned long ttbr; ttbr = read_sysreg(ttbr1_el1); - /* reserved_ttbr0 placed at the end of swapper_pg_dir */ - write_sysreg(ttbr + SWAPPER_DIR_SIZE, ttbr0_el1); + /* reserved_ttbr0 placed before swapper_pg_dir */ + write_sysreg(ttbr - RESERVED_TTBR0_SIZE, ttbr0_el1); isb(); /* Set reserved ASID */ ttbr &= ~TTBR_ASID_MASK; |